sugar question

What is the difference between sugars and sugar alcohols and how we absorb them?
One protein bar says 2 grams sugar and 15 sugar alcohol while another say 20 grams sugar.

I googled this:

A. Sugar alcohols are reduced calorie sugar substitutes that can be found in sugar-free candies, desserts, chewing gum, and other products.  Sugar alcohols do not have as much effect on blood sugar in comparison to regular table sugar.

 

If a food contains more than 5 grams sugar alcohol, the American Diabetes Association recommends subtracting 1/2 of the sugar alcohol grams from the total carbohydrate in a food.  For example, if a food contains 18 grams total carbohydrate and 6 grams sugar alcohols, subtract 3 grams sugar alcohol (1/2 the amount in the food) from 18 grams carbohydrate to equal 15 grams total carbohydrate.

 

A word of caution, sugar alcohols in excess can cause diarrhea and therefore should be used in moderation.

 

With regards to the amount of sugar to have each day... the thinking has shifted to counting total carbohydrates instead of only sugar.  You should ask your doctor for a referral to a registered dietitian and certified diabetes educator to help you with the amount of carbohydrate you should consume.  Below is a link for more information:

Sugar alcohols have a low/zero glycemic index so that once consumed have little effect on the consumer's blood glucose.  They also can cause some folks some gastrointestinal issues, like gas, bloating, nausea, diarrhea,...Refined sugar has a high glycemic index and can cause your blood glucose to spike and then drop dramatically.  If you can tolerate the sugar alcohols, you should choose the one with less refined sugar.  The refined sugar may cause dumping as well.  
That being said, it's easier, cheaper and healthier (in my opinion) to have some tuna or a piece of cheese!  
 

some people may get reaction to SA - I know I do. In many differnt ways.  In theory - we should not absorb any and it should not affect our blood sugar. But that in average. I am not average. SA do affect me. I do dump on too many,  get belly distress (small to severe depends how many SA were in my food) and even had RH after consuming food with SA. It is carb after all.
You only can determine (by diet and elimination) if and how they affect you.  

Thanks for the info.  How tall are you?  I was shocked to see you weigh 165 and wear a size 8.  Drives me nuts that I am at 152 and couldn't squeeze into a size 8 if I wanted to andf I am 5'4"

lol... I am 5'4".. yea... but I do have a large frame and low body fat % ~20% (low for a woman). When I got down to 150 - I was size 4...
Now - at 163 - I wear 8's and 6's... bottom. 8 or 10 - tops. (boobs, natural)

The weight is not the only indication - it is your frame (can be judges on shoe size, hands - mine is 9.5 M to wide) plus the muscles. Muscles  take much less space than fat.
But that also mean - that I can't go below 155 - or it looks and feels sickly for me. . At 155 - most likely - I will be loose 6, tight 4...  Atlethic build...

Sugar alcohols can cause a lot of gastrointestinal distress, so be cautious in trying them. They tend to have a laxative effect.

In theory we don't have to count sugar alcohols in total carb count because they minimally absorb. You can subtract fiber and sugar alcohols from the total number of carbohydrate grams per serving and call a product "low carb." Just be aware that this does NOT mean it's totally safe and will absolutely not bother you or impact your weight. It's not magic stuff.